A separation-type air conditioning device is one type of conventional refrigeration device. This type of air conditioning device is mainly provided with a heat source unit having a compressor and a heat-source-side heat exchanger, a utilization unit having a utilization-side heat exchanger, and a liquid refrigerant connection pipe and gas refrigerant connection pipe for connecting the units to each other.
In this type of air conditioning device, the sequence of implementation from the work of device installation, piping, and wiring until the start of operation mainly includes the four steps below.
(1) Device installation, piping, and wiring
(2) Evacuation of the refrigerant connection pipe
(3) Loading of additional refrigerant (performed as needed)
(4) Start of operation
Installation of the type of air conditioning device described above has drawbacks in that the process of evacuating the refrigerant connection pipe necessitates the complex operations of connecting a vacuum pump to the liquid refrigerant connection pipe and the gas refrigerant connection pipe, and performing other operations that are important for preventing release of refrigerant into the atmosphere; degradation of the refrigerant and refrigerator oil due to residual oxygen gas; an increase in operating pressure due to non-condensable gases primarily composed of oxygen gas, nitrogen gas, and other atmospheric components; and other effects.
In order to overcome these drawbacks, an air conditioning device is proposed whereby the non-condensable gas retained in the refrigerant connection pipe after device installation, piping, and wiring is removed by adsorption by connecting a gas separation device filled with an adsorbent agent to the refrigerant circuit, and recirculating the refrigerant. Evacuation using a vacuum pump can thereby be omitted, and implementation of the air conditioning device can be simplified (see Japanese Laid Open Patent Publication No. 5-69571, for example). However, since a large quantity of the adsorbent agent must be used in order to adsorb all of the non-condensable gas included in the refrigerant in this air conditioning device, the device as a whole is enlarged, and is difficult to actually mount in a refrigeration device.
An air conditioning device is also proposed in which a fixture having a separation membrane is connected to the refrigerant circuit, refrigerant sealed into the heat source unit in advance is caused to fill the entire refrigerant circuit, and the non-condensable gas trapped in the refrigerant connection pipe after device installation, piping, and wiring is mixed with the refrigerant, after which the gas mixture of the refrigerant and the non-condensable gas is fed to the separation membrane without increasing the pressure thereof, and the non-condensable gas is separated and removed from the refrigerant. Evacuation using a vacuum pump can thereby be omitted, and implementation of the air conditioning device can be simplified (see Japanese Laid Open Patent Publication No. 10-213363, for example). However, this air conditioning device has drawbacks in that the separation efficiency of the non-condensable gas in the separation membrane is low because it is impossible to increase the pressure difference between the primary side (specifically, the inside of the refrigerant circuit) of the separation membrane and the secondary side (specifically, the outside of the refrigerant circuit).